US Forest Service officials have closed Willow Creek Reservoir in Grand County because of a potential blue-green algae bloom.

Willow Creek Reservoir is normally open to non-motorized recreation. The Forest Service says it is working with county officials, Colorado Parks and Wildlife, the Bureau of Reclamation, Northern Water and others to try to keep the public safe and assess when the area can reopen.

Some types of blue-green algae can produce toxins that may be harmful to humans and pets at elevated concentrations.

When water temperatures are warmer, commonly 68-77 degrees, and extra nutrients are present, the algae can multiply to form algal blooms. Some of the algae can start producing toxic compounds called cyanotoxins.

Currently there is no method to remove toxins from lakes.

The Colorado Department of Public Health and Environment recommends the following:

• Keep kids out

• No pets in water

• Do not drink water

• Avoid contact with algae

Recreational exposure can occur through incidental ingestion of water containing toxins. Young children and dogs are at high risk because they are most likely to drink thefea water.